1. Signatures of asymmetry in neutron spectra and images predicted by three-dimensional radiation hydrodynamics simulations of indirect drive implosions
- Author
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Jeremy Chittenden, Nicolas Niasse, Brian Appelbe, F. Manke, K. McGlinchey, AWE Plc, and Engineering & Physical Science Research Council (EPSRC)
- Subjects
Physics ,media_common.quotation_subject ,Fluids & Plasmas ,Condensed Matter Physics ,01 natural sciences ,Asymmetry ,010305 fluids & plasmas ,0203 Classical Physics ,Nuclear physics ,0201 Astronomical And Space Sciences ,0202 Atomic, Molecular, Nuclear, Particle And Plasma Physics ,Flow velocity ,0103 physical sciences ,Neutron source ,Neutron ,Ray tracing (graphics) ,010306 general physics ,Anisotropy ,National Ignition Facility ,Inertial confinement fusion ,media_common - Abstract
We present the results of 3D simulations of indirect drive inertial confinement fusion capsules driven by the "high-foot" radiation pulse on the National Ignition Facility. The results are post-processed using a semi-deterministic ray tracing model to generate synthetic deuterium-tritium (DT) and deuterium-deuterium (DD) neutron spectra as well as primary and down scattered neutron images. Results with low-mode asymmetries are used to estimate the magnitude of anisotropy in the neutron spectra shift, width, and shape. Comparisons of primary and down scattered images highlight the lack of alignment between the neutron sources, scatter sites, and detector plane, which limits the ability to infer the rho r of the fuel from a down scattered ratio. Further calculations use high bandwidth multi-mode perturbations to induce multiple short scale length flows in the hotspot. The results indicate that the effect of fluid velocity is to produce a DT neutron spectrum with an apparently higher temperature than that inferred from the DD spectrum and which is also higher than the temperature implied by the DT to DD yield ratio. Published by AIP Publishing. more...
- Published
- 2016